src/modules/extra/m_ssl_gnutls.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
   5  *   Copyright (C) 2008 John Brooks <john.brooks@dereferenced.net>
   6  *   Copyright (C) 2006-2008 Craig Edwards <craigedwards@brainbox.cc>
   7  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
   8  *   Copyright (C) 2006 Oliver Lupton <oliverlupton@gmail.com>
   9  *
  10  * This file is part of InspIRCd.  InspIRCd is free software: you can
  11  * redistribute it and/or modify it under the terms of the GNU General Public
  12  * License as published by the Free Software Foundation, version 2.
  13  *
  14  * This program is distributed in the hope that it will be useful, but WITHOUT
  15  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  16  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  17  * details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21  */
  22
  23
  24 #include "inspircd.h"
  25 #include <gcrypt.h>
  26 #include <gnutls/gnutls.h>
  27 #include <gnutls/x509.h>
  28 #include "modules/ssl.h"
  29 #include "modules/cap.h"
  30
  31 #if ((GNUTLS_VERSION_MAJOR > 2) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR > 9) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR == 9 && GNUTLS_VERSION_PATCH >= 8))
  32 #define GNUTLS_HAS_MAC_GET_ID
  33 #include <gnutls/crypto.h>
  34 #endif
  35
  36 #ifdef _WIN32
  37 # pragma comment(lib, "libgnutls.lib")
  38 # pragma comment(lib, "libgcrypt.lib")
  39 # pragma comment(lib, "libgpg-error.lib")
  40 # pragma comment(lib, "user32.lib")
  41 # pragma comment(lib, "advapi32.lib")
  42 # pragma comment(lib, "libgcc.lib")
  43 # pragma comment(lib, "libmingwex.lib")
  44 # pragma comment(lib, "gdi32.lib")
  45 #endif
  46
  47 /* $CompileFlags: pkgconfincludes("gnutls","/gnutls/gnutls.h","") exec("libgcrypt-config --cflags") -Wno-pedantic */
  48 /* $LinkerFlags: rpath("pkg-config --libs gnutls") pkgconflibs("gnutls","/libgnutls.so","-lgnutls") exec("libgcrypt-config --libs") */
  49
  50 // These don't exist in older GnuTLS versions
  51 #if ((GNUTLS_VERSION_MAJOR > 2) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR > 1) || (GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR == 1 && GNUTLS_VERSION_MICRO >= 7))
  52 #define GNUTLS_NEW_PRIO_API
  53 #endif
  54
  55 #if(GNUTLS_VERSION_MAJOR < 2)
  56 typedef gnutls_certificate_credentials_t gnutls_certificate_credentials;
  57 typedef gnutls_dh_params_t gnutls_dh_params;
  58 #endif
  59
  60 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
  61
  62 static std::vector<gnutls_x509_crt_t> x509_certs;
  63 static gnutls_x509_privkey_t x509_key;
  64 #if(GNUTLS_VERSION_MAJOR < 2 || ( GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR < 12 ) )
  65 static int cert_callback (gnutls_session_t session, const gnutls_datum_t * req_ca_rdn, int nreqs,
  66         const gnutls_pk_algorithm_t * sign_algos, int sign_algos_length, gnutls_retr_st * st) {
  67
  68         st->type = GNUTLS_CRT_X509;
  69 #else
  70 static int cert_callback (gnutls_session_t session, const gnutls_datum_t * req_ca_rdn, int nreqs,
  71         const gnutls_pk_algorithm_t * sign_algos, int sign_algos_length, gnutls_retr2_st * st) {
  72         st->cert_type = GNUTLS_CRT_X509;
  73         st->key_type = GNUTLS_PRIVKEY_X509;
  74 #endif
  75         st->ncerts = x509_certs.size();
  76         st->cert.x509 = &x509_certs[0];
  77         st->key.x509 = x509_key;
  78         st->deinit_all = 0;
  79
  80         return 0;
  81 }
  82
  83 class RandGen : public HandlerBase2<void, char*, size_t>
  84 {
  85  public:
  86         RandGen() {}
  87         void Call(char* buffer, size_t len)
  88         {
  89                 gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
  90         }
  91 };
  92
  93 /** Represents an SSL user's extra data
  94  */
  95 class issl_session
  96 {
  97 public:
  98         StreamSocket* socket;
  99         gnutls_session_t sess;
 100         issl_status status;
 101         reference<ssl_cert> cert;
 102
 103         issl_session() : socket(NULL), sess(NULL) {}
 104 };
 105
 106 class GnuTLSIOHook : public SSLIOHook
 107 {
 108  private:
 109         void InitSession(StreamSocket* user, bool me_server)
 110         {
 111                 issl_session* session = &sessions[user->GetFd()];
 112
 113                 gnutls_init(&session->sess, me_server ? GNUTLS_SERVER : GNUTLS_CLIENT);
 114                 session->socket = user;
 115
 116                 #ifdef GNUTLS_NEW_PRIO_API
 117                 gnutls_priority_set(session->sess, priority);
 118                 #endif
 119                 gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
 120                 gnutls_dh_set_prime_bits(session->sess, dh_bits);
 121                 gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(session));
 122                 gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
 123                 gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
 124
 125                 if (me_server)
 126                         gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
 127
 128                 Handshake(session, user);
 129         }
 130
 131         void CloseSession(issl_session* session)
 132         {
 133                 if (session->sess)
 134                 {
 135                         gnutls_bye(session->sess, GNUTLS_SHUT_WR);
 136                         gnutls_deinit(session->sess);
 137                 }
 138                 session->socket = NULL;
 139                 session->sess = NULL;
 140                 session->cert = NULL;
 141                 session->status = ISSL_NONE;
 142         }
 143
 144         bool Handshake(issl_session* session, StreamSocket* user)
 145         {
 146                 int ret = gnutls_handshake(session->sess);
 147
 148                 if (ret < 0)
 149                 {
 150                         if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 151                         {
 152                                 // Handshake needs resuming later, read() or write() would have blocked.
 153
 154                                 if(gnutls_record_get_direction(session->sess) == 0)
 155                                 {
 156                                         // gnutls_handshake() wants to read() again.
 157                                         session->status = ISSL_HANDSHAKING_READ;
 158                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
 159                                 }
 160                                 else
 161                                 {
 162                                         // gnutls_handshake() wants to write() again.
 163                                         session->status = ISSL_HANDSHAKING_WRITE;
 164                                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
 165                                 }
 166                         }
 167                         else
 168                         {
 169                                 user->SetError("Handshake Failed - " + std::string(gnutls_strerror(ret)));
 170                                 CloseSession(session);
 171                                 session->status = ISSL_CLOSING;
 172                         }
 173
 174                         return false;
 175                 }
 176                 else
 177                 {
 178                         // Change the seesion state
 179                         session->status = ISSL_HANDSHAKEN;
 180
 181                         VerifyCertificate(session,user);
 182
 183                         // Finish writing, if any left
 184                         ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 185
 186                         return true;
 187                 }
 188         }
 189
 190         void VerifyCertificate(issl_session* session, StreamSocket* user)
 191         {
 192                 if (!session->sess || !user)
 193                         return;
 194
 195                 unsigned int status;
 196                 const gnutls_datum_t* cert_list;
 197                 int ret;
 198                 unsigned int cert_list_size;
 199                 gnutls_x509_crt_t cert;
 200                 char str[512];
 201                 unsigned char digest[512];
 202                 size_t digest_size = sizeof(digest);
 203                 size_t name_size = sizeof(str);
 204                 ssl_cert* certinfo = new ssl_cert;
 205                 session->cert = certinfo;
 206
 207                 /* This verification function uses the trusted CAs in the credentials
 208                  * structure. So you must have installed one or more CA certificates.
 209                  */
 210                 ret = gnutls_certificate_verify_peers2(session->sess, &status);
 211
 212                 if (ret < 0)
 213                 {
 214                         certinfo->error = std::string(gnutls_strerror(ret));
 215                         return;
 216                 }
 217
 218                 certinfo->invalid = (status & GNUTLS_CERT_INVALID);
 219                 certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
 220                 certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
 221                 certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);
 222
 223                 /* Up to here the process is the same for X.509 certificates and
 224                  * OpenPGP keys. From now on X.509 certificates are assumed. This can
 225                  * be easily extended to work with openpgp keys as well.
 226                  */
 227                 if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
 228                 {
 229                         certinfo->error = "No X509 keys sent";
 230                         return;
 231                 }
 232
 233                 ret = gnutls_x509_crt_init(&cert);
 234                 if (ret < 0)
 235                 {
 236                         certinfo->error = gnutls_strerror(ret);
 237                         return;
 238                 }
 239
 240                 cert_list_size = 0;
 241                 cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
 242                 if (cert_list == NULL)
 243                 {
 244                         certinfo->error = "No certificate was found";
 245                         goto info_done_dealloc;
 246                 }
 247
 248                 /* This is not a real world example, since we only check the first
 249                  * certificate in the given chain.
 250                  */
 251
 252                 ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
 253                 if (ret < 0)
 254                 {
 255                         certinfo->error = gnutls_strerror(ret);
 256                         goto info_done_dealloc;
 257                 }
 258
 259                 gnutls_x509_crt_get_dn(cert, str, &name_size);
 260                 certinfo->dn = str;
 261
 262                 gnutls_x509_crt_get_issuer_dn(cert, str, &name_size);
 263                 certinfo->issuer = str;
 264
 265                 if ((ret = gnutls_x509_crt_get_fingerprint(cert, hash, digest, &digest_size)) < 0)
 266                 {
 267                         certinfo->error = gnutls_strerror(ret);
 268                 }
 269                 else
 270                 {
 271                         certinfo->fingerprint = BinToHex(digest, digest_size);
 272                 }
 273
 274                 /* Beware here we do not check for errors.
 275                  */
 276                 if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
 277                 {
 278                         certinfo->error = "Not activated, or expired certificate";
 279                 }
 280
 281 info_done_dealloc:
 282                 gnutls_x509_crt_deinit(cert);
 283         }
 284
 285         static const char* UnknownIfNULL(const char* str)
 286         {
 287                 return str ? str : "UNKNOWN";
 288         }
 289
 290         static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t session_wrap, void* buffer, size_t size)
 291         {
 292                 issl_session* session = reinterpret_cast<issl_session*>(session_wrap);
 293                 if (session->socket->GetEventMask() & FD_READ_WILL_BLOCK)
 294                 {
 295 #ifdef _WIN32
 296                         gnutls_transport_set_errno(session->sess, EAGAIN);
 297 #else
 298                         errno = EAGAIN;
 299 #endif
 300                         return -1;
 301                 }
 302
 303                 int rv = ServerInstance->SE->Recv(session->socket, reinterpret_cast<char *>(buffer), size, 0);
 304
 305 #ifdef _WIN32
 306                 if (rv < 0)
 307                 {
 308                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 309                          * and then set errno appropriately.
 310                          * The gnutls library may also have a different errno variable than us, see
 311                          * gnutls_transport_set_errno(3).
 312                          */
 313                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 314                 }
 315 #endif
 316
 317                 if (rv < (int)size)
 318                         ServerInstance->SE->ChangeEventMask(session->socket, FD_READ_WILL_BLOCK);
 319                 return rv;
 320         }
 321
 322         static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t session_wrap, const void* buffer, size_t size)
 323         {
 324                 issl_session* session = reinterpret_cast<issl_session*>(session_wrap);
 325                 if (session->socket->GetEventMask() & FD_WRITE_WILL_BLOCK)
 326                 {
 327 #ifdef _WIN32
 328                         gnutls_transport_set_errno(session->sess, EAGAIN);
 329 #else
 330                         errno = EAGAIN;
 331 #endif
 332                         return -1;
 333                 }
 334
 335                 int rv = ServerInstance->SE->Send(session->socket, reinterpret_cast<const char *>(buffer), size, 0);
 336
 337 #ifdef _WIN32
 338                 if (rv < 0)
 339                 {
 340                         /* Windows doesn't use errno, but gnutls does, so check SocketEngine::IgnoreError()
 341                          * and then set errno appropriately.
 342                          * The gnutls library may also have a different errno variable than us, see
 343                          * gnutls_transport_set_errno(3).
 344                          */
 345                         gnutls_transport_set_errno(session->sess, SocketEngine::IgnoreError() ? EAGAIN : errno);
 346                 }
 347 #endif
 348
 349                 if (rv < (int)size)
 350                         ServerInstance->SE->ChangeEventMask(session->socket, FD_WRITE_WILL_BLOCK);
 351                 return rv;
 352         }
 353
 354  public:
 355         issl_session* sessions;
 356         gnutls_certificate_credentials_t x509_cred;
 357
 358         gnutls_digest_algorithm_t hash;
 359         #ifdef GNUTLS_NEW_PRIO_API
 360         gnutls_priority_t priority;
 361         #endif
 362         int dh_bits;
 363
 364         GnuTLSIOHook(Module* parent)
 365                 : SSLIOHook(parent, "ssl/gnutls")
 366         {
 367                 sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
 368         }
 369
 370         ~GnuTLSIOHook()
 371         {
 372                 delete[] sessions;
 373         }
 374
 375         void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
 376         {
 377                 issl_session* session = &sessions[user->GetFd()];
 378
 379                 /* For STARTTLS: Don't try and init a session on a socket that already has a session */
 380                 if (session->sess)
 381                         return;
 382
 383                 InitSession(user, true);
 384         }
 385
 386         void OnStreamSocketConnect(StreamSocket* user) CXX11_OVERRIDE
 387         {
 388                 InitSession(user, false);
 389         }
 390
 391         void OnStreamSocketClose(StreamSocket* user) CXX11_OVERRIDE
 392         {
 393                 CloseSession(&sessions[user->GetFd()]);
 394         }
 395
 396         int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
 397         {
 398                 issl_session* session = &sessions[user->GetFd()];
 399
 400                 if (!session->sess)
 401                 {
 402                         CloseSession(session);
 403                         user->SetError("No SSL session");
 404                         return -1;
 405                 }
 406
 407                 if (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE)
 408                 {
 409                         // The handshake isn't finished, try to finish it.
 410
 411                         if(!Handshake(session, user))
 412                         {
 413                                 if (session->status != ISSL_CLOSING)
 414                                         return 0;
 415                                 return -1;
 416                         }
 417                 }
 418
 419                 // If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
 420
 421                 if (session->status == ISSL_HANDSHAKEN)
 422                 {
 423                         char* buffer = ServerInstance->GetReadBuffer();
 424                         size_t bufsiz = ServerInstance->Config->NetBufferSize;
 425                         int ret = gnutls_record_recv(session->sess, buffer, bufsiz);
 426                         if (ret > 0)
 427                         {
 428                                 recvq.append(buffer, ret);
 429                                 return 1;
 430                         }
 431                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
 432                         {
 433                                 return 0;
 434                         }
 435                         else if (ret == 0)
 436                         {
 437                                 user->SetError("Connection closed");
 438                                 CloseSession(session);
 439                                 return -1;
 440                         }
 441                         else
 442                         {
 443                                 user->SetError(gnutls_strerror(ret));
 444                                 CloseSession(session);
 445                                 return -1;
 446                         }
 447                 }
 448                 else if (session->status == ISSL_CLOSING)
 449                         return -1;
 450
 451                 return 0;
 452         }
 453
 454         int OnStreamSocketWrite(StreamSocket* user, std::string& sendq) CXX11_OVERRIDE
 455         {
 456                 issl_session* session = &sessions[user->GetFd()];
 457
 458                 if (!session->sess)
 459                 {
 460                         CloseSession(session);
 461                         user->SetError("No SSL session");
 462                         return -1;
 463                 }
 464
 465                 if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
 466                 {
 467                         // The handshake isn't finished, try to finish it.
 468                         Handshake(session, user);
 469                         if (session->status != ISSL_CLOSING)
 470                                 return 0;
 471                         return -1;
 472                 }
 473
 474                 int ret = 0;
 475
 476                 if (session->status == ISSL_HANDSHAKEN)
 477                 {
 478                         ret = gnutls_record_send(session->sess, sendq.data(), sendq.length());
 479
 480                         if (ret == (int)sendq.length())
 481                         {
 482                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_WRITE);
 483                                 return 1;
 484                         }
 485                         else if (ret > 0)
 486                         {
 487                                 sendq = sendq.substr(ret);
 488                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 489                                 return 0;
 490                         }
 491                         else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
 492                         {
 493                                 ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
 494                                 return 0;
 495                         }
 496                         else // (ret < 0)
 497                         {
 498                                 user->SetError(gnutls_strerror(ret));
 499                                 CloseSession(session);
 500                                 return -1;
 501                         }
 502                 }
 503
 504                 return 0;
 505         }
 506
 507         ssl_cert* GetCertificate(StreamSocket* sock) CXX11_OVERRIDE
 508         {
 509                 int fd = sock->GetFd();
 510                 issl_session* session = &sessions[fd];
 511                 return session->cert;
 512         }
 513
 514         void TellCiphersAndFingerprint(LocalUser* user)
 515         {
 516                 const gnutls_session_t& sess = sessions[user->eh.GetFd()].sess;
 517                 if (sess)
 518                 {
 519                         std::string text = "*** You are connected using SSL cipher '";
 520
 521                         text += UnknownIfNULL(gnutls_kx_get_name(gnutls_kx_get(sess)));
 522                         text.append("-").append(UnknownIfNULL(gnutls_cipher_get_name(gnutls_cipher_get(sess)))).append("-");
 523                         text.append(UnknownIfNULL(gnutls_mac_get_name(gnutls_mac_get(sess)))).append("'");
 524
 525                         ssl_cert* cert = sessions[user->eh.GetFd()].cert;
 526                         if (!cert->fingerprint.empty())
 527                                 text += " and your SSL fingerprint is " + cert->fingerprint;
 528
 529                         user->WriteNotice(text);
 530                 }
 531         }
 532 };
 533
 534 class CommandStartTLS : public SplitCommand
 535 {
 536         IOHook& hook;
 537
 538  public:
 539         bool enabled;
 540         CommandStartTLS(Module* mod, IOHook& Hook)
 541                 : SplitCommand(mod, "STARTTLS")
 542                 , hook(Hook)
 543         {
 544                 enabled = true;
 545                 works_before_reg = true;
 546         }
 547
 548         CmdResult HandleLocal(const std::vector<std::string> &parameters, LocalUser *user)
 549         {
 550                 if (!enabled)
 551                 {
 552                         user->WriteNumeric(691, "%s :STARTTLS is not enabled", user->nick.c_str());
 553                         return CMD_FAILURE;
 554                 }
 555
 556                 if (user->registered == REG_ALL)
 557                 {
 558                         user->WriteNumeric(691, "%s :STARTTLS is not permitted after client registration is complete", user->nick.c_str());
 559                 }
 560                 else
 561                 {
 562                         if (!user->eh.GetIOHook())
 563                         {
 564                                 user->WriteNumeric(670, "%s :STARTTLS successful, go ahead with TLS handshake", user->nick.c_str());
 565                                 /* We need to flush the write buffer prior to adding the IOHook,
 566                                  * otherwise we'll be sending this line inside the SSL session - which
 567                                  * won't start its handshake until the client gets this line. Currently,
 568                                  * we assume the write will not block here; this is usually safe, as
 569                                  * STARTTLS is sent very early on in the registration phase, where the
 570                                  * user hasn't built up much sendq. Handling a blocked write here would
 571                                  * be very annoying.
 572                                  */
 573                                 user->eh.DoWrite();
 574                                 user->eh.AddIOHook(&hook);
 575                                 hook.OnStreamSocketAccept(&user->eh, NULL, NULL);
 576                         }
 577                         else
 578                                 user->WriteNumeric(691, "%s :STARTTLS failure", user->nick.c_str());
 579                 }
 580
 581                 return CMD_FAILURE;
 582         }
 583 };
 584
 585 class ModuleSSLGnuTLS : public Module
 586 {
 587         GnuTLSIOHook iohook;
 588
 589         gnutls_dh_params_t dh_params;
 590
 591         std::string sslports;
 592
 593         bool cred_alloc;
 594         bool dh_alloc;
 595
 596         RandGen randhandler;
 597         CommandStartTLS starttls;
 598
 599         GenericCap capHandler;
 600
 601  public:
 602         ModuleSSLGnuTLS()
 603                 : iohook(this), starttls(this, iohook), capHandler(this, "tls")
 604         {
 605                 gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
 606
 607                 gnutls_global_init(); // This must be called once in the program
 608                 gnutls_x509_privkey_init(&x509_key);
 609
 610                 #ifdef GNUTLS_NEW_PRIO_API
 611                 // Init this here so it's always initialized, avoids an extra boolean
 612                 gnutls_priority_init(&iohook.priority, "NORMAL", NULL);
 613                 #endif
 614
 615                 cred_alloc = false;
 616                 dh_alloc = false;
 617         }
 618
 619         void init() CXX11_OVERRIDE
 620         {
 621                 // Needs the flag as it ignores a plain /rehash
 622                 OnModuleRehash(NULL,"ssl");
 623
 624                 ServerInstance->GenRandom = &randhandler;
 625
 626                 // Void return, guess we assume success
 627                 gnutls_certificate_set_dh_params(iohook.x509_cred, dh_params);
 628
 629                 ServerInstance->Modules->AddService(iohook);
 630                 ServerInstance->Modules->AddService(starttls);
 631         }
 632
 633         void OnRehash(User* user) CXX11_OVERRIDE
 634         {
 635                 sslports.clear();
 636
 637                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 638                 starttls.enabled = Conf->getBool("starttls", true);
 639
 640                 if (Conf->getBool("showports", true))
 641                 {
 642                         sslports = Conf->getString("advertisedports");
 643                         if (!sslports.empty())
 644                                 return;
 645
 646                         for (size_t i = 0; i < ServerInstance->ports.size(); i++)
 647                         {
 648                                 ListenSocket* port = ServerInstance->ports[i];
 649                                 if (port->bind_tag->getString("ssl") != "gnutls")
 650                                         continue;
 651
 652                                 const std::string& portid = port->bind_desc;
 653                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Enabling SSL for port %s", portid.c_str());
 654
 655                                 if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
 656                                 {
 657                                         /*
 658                                          * Found an SSL port for clients that is not bound to 127.0.0.1 and handled by us, display
 659                                          * the IP:port in ISUPPORT.
 660                                          *
 661                                          * We used to advertise all ports seperated by a ';' char that matched the above criteria,
 662                                          * but this resulted in too long ISUPPORT lines if there were lots of ports to be displayed.
 663                                          * To solve this by default we now only display the first IP:port found and let the user
 664                                          * configure the exact value for the 005 token, if necessary.
 665                                          */
 666                                         sslports = portid;
 667                                         break;
 668                                 }
 669                         }
 670                 }
 671         }
 672
 673         void OnModuleRehash(User* user, const std::string &param) CXX11_OVERRIDE
 674         {
 675                 if(param != "ssl")
 676                         return;
 677
 678                 std::string keyfile;
 679                 std::string certfile;
 680                 std::string cafile;
 681                 std::string crlfile;
 682                 OnRehash(user);
 683
 684                 ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
 685
 686                 cafile = ServerInstance->Config->Paths.PrependConfig(Conf->getString("cafile", "ca.pem"));
 687                 crlfile = ServerInstance->Config->Paths.PrependConfig(Conf->getString("crlfile", "crl.pem"));
 688                 certfile = ServerInstance->Config->Paths.PrependConfig(Conf->getString("certfile", "cert.pem"));
 689                 keyfile = ServerInstance->Config->Paths.PrependConfig(Conf->getString("keyfile", "key.pem"));
 690                 int dh_bits = Conf->getInt("dhbits");
 691                 std::string hashname = Conf->getString("hash", "md5");
 692
 693                 // The GnuTLS manual states that the gnutls_set_default_priority()
 694                 // call we used previously when initializing the session is the same
 695                 // as setting the "NORMAL" priority string.
 696                 // Thus if the setting below is not in the config we will behave exactly
 697                 // the same as before, when the priority setting wasn't available.
 698                 std::string priorities = Conf->getString("priority", "NORMAL");
 699
 700                 if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
 701                         dh_bits = 1024;
 702
 703                 iohook.dh_bits = dh_bits;
 704
 705                 // As older versions of gnutls can't do this, let's disable it where needed.
 706 #ifdef GNUTLS_HAS_MAC_GET_ID
 707                 // As gnutls_digest_algorithm_t and gnutls_mac_algorithm_t are mapped 1:1, we can do this
 708                 // There is no gnutls_dig_get_id() at the moment, but it may come later
 709                 iohook.hash = (gnutls_digest_algorithm_t)gnutls_mac_get_id(hashname.c_str());
 710                 if (iohook.hash == GNUTLS_DIG_UNKNOWN)
 711                         throw ModuleException("Unknown hash type " + hashname);
 712
 713                 // Check if the user is walking around with their head in the ass,
 714                 // giving us something that is a valid MAC but not digest
 715                 gnutls_hash_hd_t is_digest;
 716                 if (gnutls_hash_init(&is_digest, iohook.hash) < 0)
 717                         throw ModuleException("Unknown hash type " + hashname);
 718                 gnutls_hash_deinit(is_digest, NULL);
 719 #else
 720                 if (hashname == "md5")
 721                         iohook.hash = GNUTLS_DIG_MD5;
 722                 else if (hashname == "sha1")
 723                         iohook.hash = GNUTLS_DIG_SHA1;
 724                 else
 725                         throw ModuleException("Unknown hash type " + hashname);
 726 #endif
 727
 728                 int ret;
 729
 730                 if (dh_alloc)
 731                 {
 732                         gnutls_dh_params_deinit(dh_params);
 733                         dh_alloc = false;
 734                         dh_params = NULL;
 735                 }
 736
 737                 if (cred_alloc)
 738                 {
 739                         // Deallocate the old credentials
 740                         gnutls_certificate_free_credentials(iohook.x509_cred);
 741
 742                         for(unsigned int i=0; i < x509_certs.size(); i++)
 743                                 gnutls_x509_crt_deinit(x509_certs[i]);
 744                         x509_certs.clear();
 745                 }
 746
 747                 ret = gnutls_certificate_allocate_credentials(&iohook.x509_cred);
 748                 cred_alloc = (ret >= 0);
 749                 if (!cred_alloc)
 750                         ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
 751
 752                 if((ret =gnutls_certificate_set_x509_trust_file(iohook.x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 753                         ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Failed to set X.509 trust file '%s': %s", cafile.c_str(), gnutls_strerror(ret));
 754
 755                 if((ret = gnutls_certificate_set_x509_crl_file (iohook.x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
 756                         ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Failed to set X.509 CRL file '%s': %s", crlfile.c_str(), gnutls_strerror(ret));
 757
 758                 FileReader reader;
 759
 760                 reader.Load(certfile);
 761                 std::string cert_string = reader.GetString();
 762                 gnutls_datum_t cert_datum = { (unsigned char*)cert_string.data(), static_cast<unsigned int>(cert_string.length()) };
 763
 764                 reader.Load(keyfile);
 765                 std::string key_string = reader.GetString();
 766                 gnutls_datum_t key_datum = { (unsigned char*)key_string.data(), static_cast<unsigned int>(key_string.length()) };
 767
 768                 // If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
 769                 unsigned int certcount = 3;
 770                 x509_certs.resize(certcount);
 771                 ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 772                 if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER)
 773                 {
 774                         // the buffer wasn't big enough to hold all certs but gnutls updated certcount to the number of available certs, try again with a bigger buffer
 775                         x509_certs.resize(certcount);
 776                         ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
 777                 }
 778
 779                 if (ret <= 0)
 780                 {
 781                         // clear the vector so we won't call gnutls_x509_crt_deinit() on the (uninited) certs later
 782                         x509_certs.clear();
 783                         throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + "): " + ((ret < 0) ? (std::string(gnutls_strerror(ret))) : "No certs could be read"));
 784                 }
 785                 x509_certs.resize(ret);
 786
 787                 if((ret = gnutls_x509_privkey_import(x509_key, &key_datum, GNUTLS_X509_FMT_PEM)) < 0)
 788                         throw ModuleException("Unable to load GnuTLS server private key (" + keyfile + "): " + std::string(gnutls_strerror(ret)));
 789
 790                 if((ret = gnutls_certificate_set_x509_key(iohook.x509_cred, &x509_certs[0], certcount, x509_key)) < 0)
 791                         throw ModuleException("Unable to set GnuTLS cert/key pair: " + std::string(gnutls_strerror(ret)));
 792
 793                 #ifdef GNUTLS_NEW_PRIO_API
 794                 // It's safe to call this every time as we cannot have this uninitialized, see constructor and below.
 795                 gnutls_priority_deinit(iohook.priority);
 796
 797                 // Try to set the priorities for ciphers, kex methods etc. to the user supplied string
 798                 // If the user did not supply anything then the string is already set to "NORMAL"
 799                 const char* priocstr = priorities.c_str();
 800                 const char* prioerror;
 801
 802                 if ((ret = gnutls_priority_init(&iohook.priority, priocstr, &prioerror)) < 0)
 803                 {
 804                         // gnutls did not understand the user supplied string, log and fall back to the default priorities
 805                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Failed to set priorities to \"%s\": %s Syntax error at position %u, falling back to default (NORMAL)", priorities.c_str(), gnutls_strerror(ret), (unsigned int) (prioerror - priocstr));
 806                         gnutls_priority_init(&iohook.priority, "NORMAL", NULL);
 807                 }
 808
 809                 #else
 810                 if (priorities != "NORMAL")
 811                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "You've set <gnutls:priority> to a value other than the default, but this is only supported with GnuTLS v2.1.7 or newer. Your GnuTLS version is older than that so the option will have no effect.");
 812                 #endif
 813
 814                 #if(GNUTLS_VERSION_MAJOR < 2 || ( GNUTLS_VERSION_MAJOR == 2 && GNUTLS_VERSION_MINOR < 12 ) )
 815                 gnutls_certificate_client_set_retrieve_function (iohook.x509_cred, cert_callback);
 816                 #else
 817                 gnutls_certificate_set_retrieve_function (iohook.x509_cred, cert_callback);
 818                 #endif
 819                 ret = gnutls_dh_params_init(&dh_params);
 820                 dh_alloc = (ret >= 0);
 821                 if (!dh_alloc)
 822                 {
 823                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Failed to initialise DH parameters: %s", gnutls_strerror(ret));
 824                         return;
 825                 }
 826
 827                 std::string dhfile = Conf->getString("dhfile");
 828                 if (!dhfile.empty())
 829                 {
 830                         // Try to load DH params from file
 831                         reader.Load(dhfile);
 832                         std::string dhstring = reader.GetString();
 833                         gnutls_datum_t dh_datum = { (unsigned char*)dhstring.data(), static_cast<unsigned int>(dhstring.length()) };
 834
 835                         if ((ret = gnutls_dh_params_import_pkcs3(dh_params, &dh_datum, GNUTLS_X509_FMT_PEM)) < 0)
 836                         {
 837                                 // File unreadable or GnuTLS was unhappy with the contents, generate the DH primes now
 838                                 ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Generating DH parameters because I failed to load them from file '%s': %s", dhfile.c_str(), gnutls_strerror(ret));
 839                                 GenerateDHParams();
 840                         }
 841                 }
 842                 else
 843                 {
 844                         GenerateDHParams();
 845                 }
 846         }
 847
 848         void GenerateDHParams()
 849         {
 850                 // Generate Diffie Hellman parameters - for use with DHE
 851                 // kx algorithms. These should be discarded and regenerated
 852                 // once a day, once a week or once a month. Depending on the
 853                 // security requirements.
 854
 855                 if (!dh_alloc)
 856                         return;
 857
 858                 int ret;
 859
 860                 if((ret = gnutls_dh_params_generate2(dh_params, iohook.dh_bits)) < 0)
 861                         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Failed to generate DH parameters (%d bits): %s", iohook.dh_bits, gnutls_strerror(ret));
 862         }
 863
 864         ~ModuleSSLGnuTLS()
 865         {
 866                 for(unsigned int i=0; i < x509_certs.size(); i++)
 867                         gnutls_x509_crt_deinit(x509_certs[i]);
 868
 869                 gnutls_x509_privkey_deinit(x509_key);
 870                 #ifdef GNUTLS_NEW_PRIO_API
 871                 gnutls_priority_deinit(iohook.priority);
 872                 #endif
 873
 874                 if (dh_alloc)
 875                         gnutls_dh_params_deinit(dh_params);
 876                 if (cred_alloc)
 877                         gnutls_certificate_free_credentials(iohook.x509_cred);
 878
 879                 gnutls_global_deinit();
 880                 ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
 881         }
 882
 883         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
 884         {
 885                 if(target_type == TYPE_USER)
 886                 {
 887                         LocalUser* user = IS_LOCAL(static_cast<User*>(item));
 888
 889                         if (user && user->eh.GetIOHook() == &iohook)
 890                         {
 891                                 // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
 892                                 // Potentially there could be multiple SSL modules loaded at once on different ports.
 893                                 ServerInstance->Users->QuitUser(user, "SSL module unloading");
 894                         }
 895                 }
 896         }
 897
 898         Version GetVersion() CXX11_OVERRIDE
 899         {
 900                 return Version("Provides SSL support for clients", VF_VENDOR);
 901         }
 902
 903         void On005Numeric(std::map<std::string, std::string>& tokens) CXX11_OVERRIDE
 904         {
 905                 if (!sslports.empty())
 906                         tokens["SSL"] = sslports;
 907                 if (starttls.enabled)
 908                         tokens["STARTTLS"];
 909         }
 910
 911         void OnHookIO(StreamSocket* user, ListenSocket* lsb) CXX11_OVERRIDE
 912         {
 913                 if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "gnutls")
 914                 {
 915                         /* Hook the user with our module */
 916                         user->AddIOHook(&iohook);
 917                 }
 918         }
 919
 920         void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
 921         {
 922                 if (user->eh.GetIOHook() == &iohook)
 923                         iohook.TellCiphersAndFingerprint(user);
 924         }
 925
 926         void OnEvent(Event& ev) CXX11_OVERRIDE
 927         {
 928                 if (starttls.enabled)
 929                         capHandler.HandleEvent(ev);
 930         }
 931 };
 932
 933 MODULE_INIT(ModuleSSLGnuTLS)